Inliners International Forums General Discussion Engines Hardened Valve Seat Inserts and unleaded fuel . . .

R;

They can't afford to.

Here in Calfornia we have a State agency called the Bureau of Automotive Repair (BAR). It was created in 1974 to 'police' auto repair shops, Garages, New car Dealer Service(s), Transmisssion and Auto Body Shops.

To do automotive repair work here you MUST be registered with them. Once this occurs; They tell YOU what your 'rights' are and how to run your business.

When this all began; we (those in the biz) felt it would get rid of the "crooks/dummys" therein and help everyone.

However; like any other bureaucracy it has 'run amock'...

Today; The BAR spends 85% of It's budget checking Smog Stations for 'rules' violations and you can't operate (public only) your vehicle without the State registration (license plate) which you MUST pass the test to get.

It no longer matters what comes out the tail pipe. What matters is what THEY say matters and they want all that crap on (or off) there.

Yeah that makes no sense, if it blows the right #'s then who care what is on or off the car. Thank god were finally getting rid of emission testing for pre OBD-II cars here in St. Louis, MO.

In other words, John, what matters is that they are justified in having a job...

So if there's a way they can put up numbers of 'violations' that they've found, they're in the clear.

I talked to one of the chemists at work. If an additive were to improve the combustion process, it would aid in the conversion of C to CO2; CO is incomplete combustion. Decreasing valve seat erosion would involve tying up the corrosives such as sulfur. He couldn't concieve how elemental tin in solid form could perform these tasks.

R-OD;

That's exactly RIGHT!! It makes NO SENSE at all.

That's the way bureaucrats work, to justify their job, like Ray said. Also; The fines are higher for cheating on SMOG than cheating a customer for $$.

You can't introduce logic into this, sorry. I've been trying since 1968 when the first ones were forced upon us.

Jason S,I believe the tin is supposed to serve the same purpose as the lead in fuel did.It aids in conducting heat from the nearly red hot exhaust valve to the valve seat and heat.This happens when the valve is on it's seat,a very short length of time.The seat erosion comes from micro welding when the hot valve hits the seat,then the valve opens taking a little seat material with it.Over time,the seat is eroded away.
Generally,the harder the engine is run,more seat erosion occurs.This varies depending on engine design,some are worse than others.
I've worked on a few Chevy 235-261 and GMC 302's every one of these heads showed signs of erosion and the exhaust seats where pounded down from wear.
A machinist can "find" a seat when grinding the valves no problem,but the valve head is recessed in which will restrict airflow and have the valve stem standing to high,requiring a pile of spring shims to get the correct spring installed height.

Jason, it's not a matter of the combustion, but the catalytic reaction that takes place during the combustion... as I understand it.

And please don't think I understand it. As I've repeated over and over, I just know it stops the seats from disappearing... seats that show a willingness to go any time it's not there.

I had a brief introduction to some of this when I did my thesis on automotive emmissions gas sensors. But, am not a chemist, so I can't effectively argue it one way or another.

The other two points the chemist made made were that if it worked there would be papers describing its operation and the carmakers would be using them.

The other chemist at work said that there is a big difference between lead in formulated gasoline and tin solids in gasoline.

It is not important enough to me to research or discuss it any further. If it is to anyone else, I recommend a literature search at your local library.

Ok I'm finaly going to add my 2cent worth to this topic.
First Off There is a very good Risk to hitting water when going to install a Hardened seat.
#1 don't DO is have a Deep seat installed at ALL This will pretty much Guarantee your going to be Hitting Water.#2 Use a Shallow seat this will lesson the problem But still No Guarantee That you won't hit water.
When ever Your going to a Bigger Valve This becomes a ISSUE with Hardened Seats.AND The Biggest REASON for this is CORE SHIFT in the head casting.
So with SOoooooooooo Many lead additives Out there
Why Run the Risk if your that worried about Hardened seats USE IT. Why Run the risk of having a Head That has been CUT Right into the water jacket NOW your Back to Square ONE.
I ran My 64 FOR the Most Part which was at the Time a Daily driver/Racer To nothing But a FULL time Racer Nearing the end of 17 Plus years AND Never seen Or had a Issue with Out running Hardened seats.And Fuel octange ranging from LCheap 87 to 112 On the track.
So like i said My 2Cent oppion.

AMEN!!

Anyone with "good sense" knows; It's the heat from the unnecessary Cat. that causes the problem, NOT the fuel etc.

The Auto MFG puts them in to CYA.

Lets put this thing 'to bed'.

But if you could run leaded fuel with a cat,, you would not have that problem w/valve seats also.

But, I know, if you run leaded fuel w/a cat ,it will eventually plug it.

MBHD

OK Lets Just Get a Little More REAL for a sec.
HOW many of you guys are Putting a 230,250,292
Motor into anything THATs even NEW Enought to Have Had a CAT on the car OR TRUCK to start with?????????? ANYTHING For The Most part BEFORE 85 DIDN'T Have a CAT.
AND ONE THING EVERYONE has also Over looked is that any Motor That Had a CAT on it ALSO HAD A AIR pump Which did Double duty to the Best that i can remember #1 which was to help Cool the valve.#2 who knows what else as far as the exhaust itself goes.
But Personaly I think this is getting BEAT to death ,AND Nobody here is builting There MOTORS For Extreme DUTY But to Either Full Race Or a Nice reliable daily drivers. But it seems that many of the machine shop guys in & around town here (oppions)That if You not racking Up close to a 100,000 miles a yr Or Building FOR Extreme Duty,
OR HIGH RPMs (Long term) & maybe? turboed ( not much imput on the turbo)Don't realy feel a need
for them in a cast Iron Head.Some said Yes But Others say NO. SO my 2cents is I guess It's up to
The one Whos having a head Built Or to Which guy/Machine shop your asking?? I guess this could turn out to be a interesting POLE/survey for MOST machine shops.

Gentlemen;

The AIR "air injection reactor" aka 'SMOG pump' was just another government 'con job' from the 60s and forced upon us in 1968.

All it does is blow air into the exhaust manifolds creating a lower HC reading at idle while robbing 2-3 Hp. from the engine @ 'run' speed. Most were all 'trashed' when they came out.

Like Larry says, this was LONG before the the Cat. came on the scene, which isn't required on 1970 vehicles today and NEVER was.

When an engine is abused by operating it for long periods with one or more valves burned through or cracked, the seat for that valve (usually exhaust) is destroyed beyond 'normal' repair procedures.

There; a steel seat is used to "save the head" for the customer and NONE of this has anything to do with the fuel being used.

The Cat. being forced upon the American (motoring) public is just another form of engine abuse because of the extra/unecessary heat it creates in the combustion chamber/process.

It's this unusual operation/abuse that require these seats (sometimes) NOT the fuel.

Commercial 'fleet' vehicles use them for "preventive maintaince" is all (to save down time) on some of their vehicles only (not all) when they ALL use the same fuel.

Machine Shop personnel can often get these facts confused in their selling dialouge.

This; Coupled with decades of government propaganda on the subject is how the isssue(s) got swiched.

The Cat came first causing the engine damage, then 'unleaded' fuel which prevents damage to the Cat. Not the "other way" around!!

This is HISTORY not opinion.
"No brag son, just fact", Walter Brennen.

The EPA does not mandate the automotive manufacture's specification of equipment to meet emission standards. It does regulate the fuel. Air pumps were a stop gap measure by the automotive manufacturers to lower unburn hydrocarbons, HC. Air was injected in the exhaust port to enhance the final burning of the unburned hydrocarbons (fuel). Dilution of the exhaust gases does not lower the emission readings as it is measured on a grams/mile basis. Or as they say in industry:

Dilution is not the solution to pollution.

I am not aware of the automotive certification test required in the late 1960's.

As far as temperatures seen by the exhaust valve being elevated are concerned, I don't understand the direct connection with the catalytic converter, especially with the modern low restriction monolith convertors. The earlier pellet type converters had significant back pressure, which restricted flow. Air was also injected into some 3-way converters. Maybe this increased temperatures at the exhaust valve by reducing exhaust flow. Running very lean air/fuel ratios can extend the burn phase time, maybe also raising exhaust temperatures.

I'm one who's glad that automotive emissions have been reduced 90%. The reduction has been costly and a pain in the butt at times. With modern fuel injection systems, ignition sytems, combustion chamber designs, and the monolithic catalytic converter, engines are more efficient, pollute less, and last longer.

Ever stand behind a 1960's or 70's vehicle for long when it's running, especially one that's been hopped up? It will choke you up in more that one way. Yes, the EPA can be unyielding and draconian at times. So can the automotive manufacturers too. In the last several years a high speed test reaching speeds of 80 mph was added to the emission certification test cycle. The reason was that the prior certification test only called for speeds to 55 mph, and manufactures such as Cadillac had different fuel injection program maps for vehicles speeds above 55 mph that did not meet the intent of the emission standards.

I have worked with air and water emission standards programs in industry, and yes the EPA and state environmental programs can be bureaucratic, misguided, deceptive, naive, and lacking results/dollar value at times. They have made a tremendous impact on our enviroment. Remember when the Ohio River was declared a fire hazard.

You in the "Peoples Republic of California" have addition problems with 1) sensitive environmental conditons due to geographical concerns - winds mountains, valleys, sunlight and 2) being in the "People's Republic of California" where government is "suppose" to solve, and therefore have its hand in so many issues.

Related emissions websites:

http://www.epa.gov/reg5oair/mobile/history.htm
http://www.epa.gov/otaq/ld-hwy.htm

Mr. Winter;

The AIR system may be designed (in theory) to do that, but in reality it just 'stirs things up' or dilutes the exhaust to change the reading at idle (only) and does NOTHING to aid air quality as the volume and # of pulses @ run speed overwhelm it etc.

The excesssive temps caused by the Cat. used/required on later 70s & early 80s vehicles is what's under discussion and also caused the MFG to add steel seats at the factory back then.

As far as 60s vehicles having an odor; simply not true. However; I agree that any 'hopped up' engine will though, as the high speed camshafts used in them don't work well at idle.

The claim of a 90% reduction in emissions is "wishfull thinking" and impossible to prove/disprove as ALL the 'numbers' generated are the governments, or their "friends".

You are "right on" is stating that EFI & HEI systems (in unison) DO reduce emssions greatly and are welcome by everyone, mostly because they reduce fuel consumption.

Your analogy of the: "Peoples Republic of California" is 'right on' as well, but understated. Over 1/3 of the vehicles that fail our SMOG test do while passing the emmisions standard(s) for HC, CO & NOX. It's all about money/power and keeping it. We just had a ballod proposition (P-87) last election that would have taxed us 7 Billion ($) for a new breaucracy using air pollution/air quaility fuel (energy) usage as it's justification.

I believe that money would have been used to fight E-87 in the mid west, or create a government sponsored fuel consortitum there.

Your statement reguarding 'geograpyhical concerns' is correct (if) you are refering to the "South Coast Air Basin" in Los Angeles. However: Those conditions were there long before the internal combustion engine. The Indians named it; 'the valley of smoke'.

Happy trails.

Well to be real, out here in Calif. most vehicles post '75 have "cats" on them to pass smog test.

Is the smog pump diluting the exhaust gasses or cooling the exhaust gasses?

I was under the impression it was cooling the exhaust gasses which tend to be a little higher on a smog motor that usually has the carb leaned out causing higher exhaust temps.

The "SMOG pump" (AIR system) pumps air into the exhause manifold in an attempt to reduce HC @ idle speed. The injection point is near the ex. valve & may have a 'cooling effect' (of sorts) at idle only.

This stiring up/dillution of HC @ idle creates a lower reading during the test procedure as it "fools" the meter.

At 'run speeds' it robs horsepower and fuel mileage which is the oposite of cleaning the air because fuel is waisted.

The cost of it is a financial disaster too. Just think of a $100+ cost (per unit) times the # of cars made in the USA and eslewhere.

In addition: There's no way anyone can do any type of (objective) research on this situation as It's illegal to remove or alter the devices.

The games "rigged" by the government here.

Most states (the other 49) just do what the EPA says which is okay, as most vehicles will pass the test with their standards W/O the "devices". Especially those with EFI/HEI systems that are 'joined' via computer.

The really 'scarey' part is many believe the government after 45+ years of SMOG propaganda. Prop 87 almost passed due to it.

Thank GOD for almost.

While we're on the subject of valve seat material,it used to be that valve jobs were common on many engines after maybe 60,000 miles back when.Now,engines maintain proper compression with 200K+ miles on them.Is it the seat material?
The build quality of US engines in the 70's was poor at best.I personally remember the massive cam failures in GM V-8's,mostly Chevy.Head coolant leaks too,the coolant got into the oil,spun bearings.The car makers had the technology to prevent these problems,but they did nothing until the imports made a serious dent in sales.
Interesting,the inline 6's of that period didn't seem to have valvetrain issues,probably cause they were so gutless,lol.
It's no secret that heavy duty engines often had the seats hardened or replaceable seats made of more durable material.
Anyways,build your engine the way ya want.I will still have the inserts put in primarily to get the valve heads where they belong and the stems at the correct height.

Tony hit the nail on the head. The chevy and gmc sixes were economy engines. This is not to say that they were bad; they just didn't have the materials and technology of the better truck engines.

John, the purpose of the air injection is to promote burning of the hydrocarbons and conversion of CO to CO2 in the exhaust system; not to fool the tester.

John, why is it only at idle that the smog pump is effective?

Jason, how does the air promote the burning of HCs?

The air contains oxygen which oxidizes both the hydrocarbons and CO.

Engines are NOT designed to (just) idle, they are desinged to 'work' @ 'run speed'. When they idle, they are turning so slow that they don't burn all the fuel, creating an excess of HC & CO.

The AIR system (in theory) is suposed to function like many have said (burn up that excess). But in reality it just stirs up things making it appear to (lower reading).

(This opinion is based on decades of servicing the 60s & 70s era engines with & W/O the system, which BTW ONLY needed valve jobs @ 60,000 miles when abused by lack of maintaince.)

If; it were/did function as planned it could only work at idle speed because of the volume (air) the pump is capable of creating. The volume/tempature of exhause gases produced @ 'run speed' (or above) far exceeds what the pump would/could ever produce and it is totally "overwhelmed" in that mode.

Simply look at any AIR systems lines to the manifold vs the size of tubing (1"+) that headers use for exhaust relief.

Further proof is the fact that when removed; the vehicle always gains preformance & fuel mileage.

Like I stated before; It's a 'con job'.

I thought this title/subject is about hardened seats??
Not all this other C#@P.

MBHD

Thanks guys for answering my off topic question.

Sorry about that MBHD.